1. Technical Field
The present invention relates to an optical system, a method and a computer readable medium. More particularly, the present invention relates to an optical system for optically calculating the thickness of a scattering medium, a method for optically calculating the thickness of a scattering medium, and a computer readable medium storing a program for use with the optical system.
2. Related Art
A known examination apparatus is used for detecting foreign substances attached to silicon crystal surfaces and/or amorphous silicon thin film surfaces, for measuring crystal defects such as oxygen precipitate formation within silicon wafers, and for measuring foreign substances within amorphous silicon thin films as disclosed, for example, in International Publication No. WO 96/028721.
The technique disclosed in the above publication, however, is incapable of calculating the thickness of scattering media.